I think that's what you might call it--when the skin on the your trigger finger gets caught in-between the trigger and the trigger guard. I noticed this happening on two Hk pistol's i recently tried. One was a rental compact 9mm P2000 and the other was a full size USP .40 cal a friend owns. I wrote it off as a fluke after trying one but then thought it might be chronic is both do it. What the hell is going on with that? Are certain pistols prone to this or is it the shooter and why?